I use I2c to configure ADV7393 with fpga(kintex7) on my custom hw. But, it has no return ack to the command that i write thro i2c protocol that complies with the datasheet. I have tried SCL frequency for 400 kHz, 200 kHz, 50 kHz. But, nothing is changed. It also comply with SDA delaying that changes after falling edge of SCL. (I tried otherwise).
I have a ADV7192A/ADV7391 evoluation board. As you can see on the datasheet, ADV7391 and ADV7393 are mostly similar encoders (not different powerups, register sets, ..). I jumpered SCL and SDA test points to my custom board and tried to configure ADV7393 whose ALSB port tied to ground (0x54). And, it failed. I tried to configure encoder and decoder chips on evaluation board from my custom board to be free running NTSC. It worked.
I checked clock that is 27Mhz, power rails (1.8V, 3.3V), reset pin and it seems nothing is wrong.
I also checked some of the issues and solutions on the community which are posted below.